Sputtering is a process used to deposit a thin layer of material onto a substrate. Such thin layers are useful in certain electronic equipment, in the production of some optical storage media (such as compact discs) and in a variety of other applications. During the sputtering process the substrate and a target are placed in a deposition chamber. The target typically a metal or metal alloy, is constructed of the material to be sputtered. For example, if one wishes to deposit ruthenium as the intermediate layer or Co—Cr—Pt—B-oxide (s) as the magnetic layer, then a target made of corresponding material is used. The target and substrate are placed in proximity to one another within the chamber and the target is bombarded with an ion beam. The high energy ions cause a portion of the target to dislodge and be re-deposited on the substrate. Unfortunately, the target is not uniformly consumed. The metal is more easily dislodged from the target in those regions where the ion beam is most intense. This generates localized depleted regions, where the target eventually wears thin. The lifetime of the target is determined by the resulting thickness of the target at its thinnest point. Due to the non-uniform consumption of the metal, the target often reaches the end of its useful life after only a fraction (approximately 30%) of the metal has been consumed. The un-sputtered metal (approximately 70%) is not used.
One method for refurbishing a sputtering target that does not pulverize the spent target is disclosed in U.S. Pat. No. 7,175,802 to Sandlin et al., entitled “Refurbishing Spent Sputtering Targets.” Sadlin et al. teach a method for refurbishing a sputtering target wherein the target and powdered metal are placed within a hot isostatic pressing (HIP) container. Hot isostatic pressing (HIP), also referred to as inert gas hot pressing (IGHP), is a technique that subjects a target to high temperature (typically 480-1300° C. depending on the metal) and high, isostatic pressure (typically on the order of 100-200 MPa) under an inert atmosphere (typically argon). Isostatic pressure is pressure that is uniformly applied from all directions. After the HIP process is complete, a fused block of metal has formed around the target. The target is separated from the fused block by “sawing and milling operations.” In addition, the sawing and milling operations which are required to isolate the refurbished target result in loss of material.